1. Field of the Invention
This invention relates to a system for computer aided design and more specifically for displaying surfaces of volumes in computer models which is required to be left unobstructed.
2. Description of Related Art
A swept volume is the space occupied by a geometric model as it travels along an arbitrary trajectory. A swept surface is the boundary of the volume. Swept surfaces and volumes play important roles in many computer-aided design applications including geometric modeling, numerical control cutter path generation, and spatial path planning.
In geometric modeling swept curves and surfaces are used to represent extrusion surfaces and surfaces of revolution. More complex geometry can be generated by using higher order sweep trajectories and generating surfaces. In robot motion planning, the swept volume can be used to evaluate paths which would not interfere with the motion of a robot. Numerical control path planning also uses swept volumes to show the removal of material by a tool.
Swept surfaces and volumes can also be applied to resolve maintainability issues that arise during the design of complex mechanical systems. The designer needs to be able to create and visualize the accessibility and removeability of individual components of the system. Typical questions related to maintainability include:
Can a mechanic remove the spark plugs?
Is there room for an improved power supply?
What is the impact on the maintenance of a system if new components are included?
In maintenance design, the swept surface of the part to be removed is called the removal envelope. The removal envelope is the surface that a component generates as it moves along a safe and feasible removal trajectory. A safe trajectory is one that a component can follow without touching other components of the system. A feasible trajectory is one that can be performed by a human.